CI steps need to be enhanced to incorporate a more e2e validation

[ashutshkumr]

Every time a collaborator makes a change in KNE, apart from unit test results, there's no other way for them to have confidence on whether something broke.

At very minimum, actions CI should include following:

• Deploy at least one topology consisting of each node type
• Deploy topology with some variations (e.g. grouped interfaces, back-to-back interfaces, etc.)
• Deploy topology with negative use cases (e.g. duplicate interface name per node, duplicate group name, duplicate node name, non-existent vendor, etc.)

It would be nice to include following validations post deployment as part of CI:

• meshnet CRD is correct
• services exposed are appropriately reachable (socket connection check)
• output of KNE topology doesn't break ONDATRA's reservation logic

My initial suggestion would be to trigger these on-pull-request and not on-push.

[alexmasi]

First step toward a more end to end presubmit: https://github.com/openconfig/kne/pull/215